NPARSEC - NTT Parallaxes of Southern Extremely Cool Objects


NPARSEC1 is major new ESO Large Programme that will perform high precision astrometric observations on 96 nights over the next 3 years, of a sample of 60 T-type brown dwarfs.

The NPARSEC Team : Ricky Smart (PI), Tinney, Andrei, Burningham, Jones, Leggett, Pinfield, Bucciarelli, Costa, Crosta, Day-Jones, Goldman, Lattanzi, Lucas, Mendez, Marocco, Penna, Qi, Vecchiato,




INSTRUMENT : SOFI Near-infrared imager.

OBSERVATIONS : High-precision differential astrometry of T dwarfs from which trigonometric parallaxes will be measured.

SCHEDULING : 8 four night observing blocks per year, over 3 years.

SAMPLE : 60 T and L9+ dwarfs accessible from the southern hemisphere.

Page prepared by Chris Tinney,

Last updated 4 October 2010.


  2. The main NPARSEC page (when available) should be referred to as the primary NPARSEC reference. Until then this page collects some materials I have worked on for the project.


In 2000-2003, I carried out an infrared paralalx program with the NTT for a small sample of about 10 T-type brown dwarfs (Tinney et al. 2003, AJ, 126, 975). That program demonstrated the suitability of 4-m class telescope for carrying out infrared parallax work - especially telescopes like the NTT which deliver excellent image quality (with median seeing of better than 0.8").

The NPARSEC program builds on that experience, by bringing together a substantial team of European, Chilean and Australian astronomers to carry out a major infrared parallax program with the NTT.

Observations for this program began on Oct 1, 2010, and will continue through to October 2012.

1 While I am an enthusiastic member of NPARSEC, I was not responsible for its acronym. I hate acronyms. They are massively over-used in science (in general) and in astronomy (in particular), and only serve to make our research less accessible to the public and other scientists. To misuse Oscar Wilde, I think that it is acronyms that are the lowest form of wit. But I'm stuck with this one.


NPARSEC is being carried out on the 3.5m New Technology Telescope (NTT) at ESO's La Silla Observatory.